c++/1785: gdb doesn't find members of base classes compiled in separate files

[thor at math dot tu-berlin dot de]

>Number:         1785
>Category:       c++
>Synopsis:       gdb doesn't find members of base classes compiled in separate files
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          patch
>Submitter-Id:   net
>Arrival-Date:   Sat Oct 02 21:38:00 UTC 2004
>Closed-Date:
>Last-Modified:
>Originator:     thor@math.tu-berlin.de
>Release:        GNU gdb 6.2
>Organization:
>Environment:

>Description:
gdb 6.2 is unable to find members of base classes if derived and main class are compiled in different files, and different directories. The bug happens in gdb/valops.c where the base classes are incorrectly accessed thru TYPE_BASECLASS(type,i). The proper version should filter the output thru check_typedef(). 

>How-To-Repeat:
Write three files in different directories, one defining class A, another defining class B derived from class A, and a third class C derived from B. Compile both with g++-3.4 -ggdb3 and link separately. Then try to print a member of class A within a method of class C. gdb will be unable to find the member, though "print *this" will print it correctly.
>Fix:
The following modification of gdb/valops.c fixes the problem:

>From line 2326 on, in file gdb/valops.c, replace the end of the function check_field_in() by:

  /* FIX THOR: Must convert the base type to the
  ** proper real base type with check_typedef.
  */
  for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--) {
    struct type *t = check_typedef (TYPE_BASECLASS (type, i));
    if (check_field_in (t, name))
      return 1;
  }


  return 0;
}
>Release-Note:
>Audit-Trail:
>Unformatted: